1. Field of the Invention
This invention relates broadly to the chemical modification of proteinaceous fibers, especially wool. In particular, the invention concerns and has as its prime object the provision of novel processes for shrinkproofing such fibers. Further objects of the invention will be evident from the following description wherein parts and percentages are by weight unless otherwise specified.
2. Description of the Prior Art
Although wool is a very useful fiber, it is often desirable to improve its properties for particular applications by chemically modifying it. For example, in U.S. Pat. No. 3,927,969, Koenig et al., have shown that wool can be reacted with zinc acetate in the presence of a polar, highboiling solvent to yield a modified wool having increased resistance to insects. Further, Koenig et al. (U.S. Pat. No. 3,867,095) have modified wool to improve its resistance to laundering shrinkage by a two-step process in which the wool is successively reacted with a cyclic acid anhydride and zinc acetate. Wool treated separately, however, either with zinc acetate or a cyclic anhydride, did not exhibit shrink resistant properties.
It is also known that the felting or shrinkage of wool can be reduced by treating wool with cupric ammonium sulfite solutions (McPhee, Textile Research Journal, Vol. 33, pages 578-579 (1963)). To this end, wool is contacted with an aqueous solution of copper sulfate and sodium sulfite, and ammonium hydroxide is added to pH 10.1. It is notable, however, that copper sulfate, in the absence of sulfite and ammonium hydroxide, does not impart shrink-resistant properties to wool (Kantouch et al., Textile Research Journal, Vol. 48, page 525 (1978)).